Intel® Stratix® 10 Hard Processor System Technical Reference Manual

ID 683222
Date 1/25/2024
Public
Document Table of Contents

16.5.10.3. Card Read Threshold Programming Examples

This section shows examples of how to program the card read threshold.
  • Choose a block size that is a multiple of 4 (the number of bytes per FIFO location), and less than 4096 (1024 FIFO locations). For example, a block size of 3072 bytes is legal, because 3072 / 4 = 768 FIFO locations.
  • For DMA mode, choose the size so that block size is a multiple of the size. For example size = 128, where block size % size = 0 (modulo operation).
  • Set the rx_wmark field = size – 1. For example, the rx_wmark field = 128 – 1 = 127.
  • Because block size > ½ FifoDepth, set the cardrdthreshold field to the block size. For example, the cardrdthreshold field = 3072 bytes.
Figure 69. FIFO Buffer content when Card Read Threshold is set to 768